JPS627199A - Printed wiring board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a printed wiring board.

[Conventional technology]

FIG. 4 is a sectional view showing a state in which mounted components are attached to a conventional printed wiring board. In the figure, 1 is a resin plate, 2
is a wiring layer formed on the resin plate 1, 3 is a through hole formed on the resin plate 1, 4 is a metal plate, 5 is a hole for a lead wire provided on the metal plate 4, and the resin plate 1 and the metal plate 4 are is bonded with an adhesive sheet 6, and the center line of the through hole 3 and the center line of the lead wire hole 5 are aligned, and the lead wire hole 5
is larger than the diameter of the through hole 3. Reference numeral 7 denotes a mounted component, and 8 a lead wire of the mounted component 7. The lead wire 8 is inserted into the lead wire hole 5 and the through hole 3, and is soldered to the through hole 3 with solder 9.

In this printed wiring board, since the metal plate 4 is bonded, heat dissipation is good.

Even if the component mounting density is high and the amount of heat emitted from the mounted components is large, the functionality of the mounted components will not deteriorate, and there is no need to use expensive mounted components having heat dissipation fins or the like.

Also, due to its high bending rigidity, even if the number of mounted components increases, the printed wiring board will not warp, making it easy to insert the printed wiring board into an electronic device and avoid contact with adjacent printed wiring boards. Not at all.

Furthermore, since the shielding effect is good, noise etc. can be effectively prevented. Therefore, it is possible to significantly expand the scope of application of the printed wiring board.

[Problem that the invention seeks to solve]

However, in such a printed wiring board, since the distance between the inner surface of the lead wire hole 5 and the lead wire 8 is very short, an electric discharge occurs between the lead wire 8 and the metal plate 4, which impairs the functionality of the electronic device. may have a serious impact. Therefore, it may be possible to increase the diameter of the lead wire hole 5, but
In this case, if the component mounting density is high, the area of the metal plate 4 will become very small, resulting in lower heat dissipation, lower bending rigidity, and further lower shielding effect.

This invention was made to solve the above-mentioned problem, and it is possible to generate electric discharge between the lead wire of the mounted component and the metal plate without increasing the diameter of the lead wire hole provided in the metal plate. The purpose of this invention is to provide a printed wiring board that does not have any problems.

[Means for solving problems]

In order to achieve this object, in the present invention, at least one of a wiring layer, a through hole, and a first lead wire hole is provided in the resin plate, a second lead wire hole is provided in the metal plate, and the metal plate is provided with a second lead wire hole. attaching an insulating film to at least the second lead wire hole, and making the center line of the through hole, the first lead wire hole substantially coincide with the center line of the second lead wire hole; The metal plate is bonded to the resin plate.

[Effect]

In such a printed wiring board, the insulating film can effectively prevent discharge from occurring between the lead wire of the mounted component and the metal plate.

〔Example〕

FIG. 1 is a sectional view showing a part of a printed wiring board according to the present invention. In this printed wiring board, since the powder coating insulating film 10 formed by powder coating is adhered to the inner surface of the lead wire hole 5 of the metal plate 4, the lead wire 8 of the mounted component 7 and the metal plate 4 can be prevented from occurring. Therefore, the lead wire hole 5
Since the diameter of the metal plate 4 can be reduced and the area of the metal plate 4 can be increased, heat dissipation is improved, bending rigidity is increased, and the shielding effect is further improved.

FIG. 2 is a sectional view showing a part of another printed wiring board according to the present invention. In this printed wiring board,
Since the resin plate 1 and the metal plate 4 are bonded together via the prepreg 11, the wiring layer 2 is formed on the surface of the resin plate 1 on the metal plate 4 side.
Even if the wiring layer 2 and the metal plate 4 are formed, it is possible to effectively prevent the wiring layer 2 and the metal plate 4 from being electrically connected.

FIG. 3 is a sectional view showing a part of another printed wiring board according to the present invention. In this printed wiring board,
This is because the printed insulating film 12 provided by printing is attached to the inner surface of the lead wire hole 5.

Similar to the printed wiring board shown in FIG. 1, even if the diameter of the lead wire hole 5 is made small, it is possible to prevent electrical discharge from occurring between the lead wire 8 and the metal plate 4.

Note that as the metal plate 4, an aluminum plate, an aluminum alloy plate, a copper plate, an iron plate, etc. can be used. Further, in the above embodiment, the multilayer wiring layer 2 is formed on the resin board 1, but the wiring layer 2 may be formed only on one or both sides of the resin board 1, or the wiring layer 2 may be formed only on one side of the resin board 1. 2, holes for lead wires may be provided in the resin plate 1.

Furthermore, in the above-mentioned embodiment, the resin plate 1 and the metal plate 4 were bonded together using the adhesive sheet 6, but prepreg was used instead.

The resin plate 1 and the metal plate 4 may be bonded together using a bonding sheet or the like. Further, in the above embodiment, the metal plate 4
Although the powder coating insulating film 10 and the printed insulating film 12 are attached to the inner surface of the lead wire hole 5, other insulating films may be attached to the inner surface of the lead wire hole 5.

〔Effect of the invention〕

As explained above, in the printed wiring board according to the present invention, even if the diameter of the lead wire hole provided in the metal plate is made small, electric discharge does not occur between the lead wire of the mounted component and the metal plate. Since it is possible to prevent this, the function of the electronic device is not seriously affected, and the heat dissipation property can be improved, the bending rigidity is increased, and the shielding effect is further improved. As described above, the effects of this invention are remarkable.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views showing a part of a printed wiring board according to the present invention, and FIG. 4 is a cross-sectional view showing a state in which mounted components are attached to a conventional printed wiring board. 1...Resin plate 2...Wiring layer 3...Through hole 4...Metal plate 5...Hole for lead wire 10...Powder coating insulating film 12...Printed insulating film spear 1... t4 diagram

Claims (3)

[Claims] (1) Provide at least one of a wiring layer, a through hole, and a first lead wire hole in the resin plate, provide a second lead wire hole in the metal plate, and provide at least the second lead wire hole in the metal plate. an insulating film is attached to the through hole, the center line of the first lead wire hole and the center line of the second lead wire hole are substantially aligned, and the metal plate is bonded to the resin plate. A printed wiring board characterized by: (2) The printed wiring board according to claim 1, wherein a powder coated insulating film is attached as the insulating film. (3) The printed wiring board according to claim 1, wherein a printed insulating film is attached as the insulating film.